Tensioning drive device



J. CLAYTON TENSIONING DRIVE DEVICE Filed May 4, 1946 [N VEN TOR.

JOSEPH CLAYTON.

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March 13, 1951 Patented Mar. 13, 1951 UNITED STATES PATENT OFFICE.

TENSIONING DRIVE DEVICE Joseph Clayton, New York, N. Y.

Application May 4, 1946, Serial No. 667,363

11 Claims.

This invention relates to tensioning devices, and more particularly to the type of take-up or tensioning device disclosed in United States Patent Number 1,705,899, granted March 19, 1929 vIn the aforesaid patent is shown and described with film winding mechanism, such as is used in motion picture projectors and the like, and such devices are commonly termed even-tension takeflip devices.

Accordingly, the present invention will be described more particularly in connection with a device for Winding film, but it will be understood that the device is applicable to many other uses where it is desired to maintain an even tension on the material being wound irrespective of the diameter of the roll of material, as the winding torque is automatically proportioned to the load.

The following specification and. the accompanying drawings disclose a preferred embodiment of the device; the construction and arrangement of the parts may be varied without,

numeral l0 denotes the back plate of a clutch which plate has preferably formed integral therei with a. hub H.

The plate has an annular outwardly extending flange l2 to which may be secured a ring driving member generally indicated by the numeral l3, which maybe adapted to receive a belt or any other drivingmeans to rotate the device. One preferred form of driving member has two rows of teeth l4, l5, to receive ai'driving chain such as commonly used in motion picture projectors.

The numeral [6 generally denotes the front plate ofthe clutch which has a flange (I which extends into the ring driving member [3 so that itlies against the flange l 2 and is secured thereto by screws as hereinafter referred to. llates I0 2 and I6 form a removable casing surrounding a friction disc to be presently described. 1

The plate l6 has a central aperture [8 therein which has a key or projection l9 fitting into a groove 20 in the internally tapered bushing 2!, which is therefore slidable in and out of said aperture.

The hub I I is bored out to accommodate a support 22 which extends into the hub. The bearing support has a shoulder 23 which, when the support is in place in the hub, is spaced from the end 24 of thehub by means of suitable adjusting washers 25, 26. The portion 53 of support 22' is received in a fixed sleeve on the machine and is fixed thereto-by a set screw or in any other suitable manner, so that the support 22 is fixed. The sleeve or arm on which the sleeve-like support is fixed may be part of the projector or magazine and is usual and therefore not shown in this drawing. g

The bushing'2 has an inner cone bearing surface 21 and the bearing support 22 has an inner cone bearing surface 28. 5

A shaft 29 has a tapered bushing 30 which {is free to revolve on the shaft and which is therefore movable therealong. This bushing is tapered as shown at 3| said taper corres onding to the taper of the cone bearing surface 28. e

A thrust washer 32 is placed on the shaft 29 and is movable therealong.

A thrust ball-bearing 33, is placed on the shaft and is freely movable therealong, and a second thrust Washer 34 is placed on the shaft.

A stop member 35 is then placed on the shaft and may be secured therealong by any suitable means, such as the set screw 36.

The outer end of the shaft 29, where it extends to the right in the figures beyond the backplate H! of the clutch, is threaded and flattened in one or more places. as shown at 31, 38, 39, in Figure 1, and a friction disc generally indicated by the numeral 40 has a central aperture which clears the threaded part of the 'shaft,but enga es the flats thereon so that the disc may be rotated by the shaft, but is free to slide therealong. The friction disc 40 has its outer peripher beveled ofi at angles which, for the sake of illustration, may be 34 degrees. "Said angular surfaces are opposed to and may engage similar angular surfaces on the insidefaces of the back plate In and the front plate l6 of the clutch.

The friction disc has an outwardly extending hub portion 4| which is tapered to fit the cone bearing surface 21 of the bushing 2|.

A pair of washers 42'. 43, are placed over the outer end of the shaft and an interiorly-threaded any other suitable manner. -sembled, with the other. parts in place as previously described, thestop member 35 and the nut 44-:may be adjusted longitudinally on shaft 29, holding all of the parts together in assembled relatiom with the friction disc 4|] floating between second clutch member.

adjusting nut 44 fits the outer threaded end 45 of the shaft and may be locked thereto by means of the set screw 46.

The left hand end of shaft 29 is adapted to support the usual film reel (not shown) containing the film to be wound and it may therefore be provided with a portion 41 which may have a key or other member 48 fitting into the usual slotted head of the film reel and the usual snap finger 49 is then moved to position at right angles to the axis of the shaft 29 to hold the reel thereon the well-known manner. Obviously any reel mounting arrangement can be used, pr'ovided'the reel is rotatably secured to the shaft 29.

It will be observed from the foregoing that the shaft 29 when assembled in the device as shown in Figure 2 is supported by the coneshaped surfaces 21, 4|, and 28, 3| and the other parts such :as hub Land the support 22 are bored out sufficiently to provide clearance for theshaft. It

willalso be observed that the friction disc 49 is supported on and revolves with the shaft without wobble, although it is longitudinally movable therealong.

The device is assembled by placing the friction disc 40- onshaft 29 between the back plate l9 and the frontplate 1 6 and securing the front and .back plate together and to the driving member |-3 by means of screws 59 as. shown in Figure 2 or When so asthe tapered surfaces on the. interior. faces of the clutch members 10 and. .IB. so that the tapered surface 5| of the friction disc 49 is in contact withthe plate ID of theclutch.

Adverting new to the aforesaid Patent 1,705,899

it will be seen that the device therein has a shaft 4 carryinga reel and similar to the shaft 29 of the instant application, and that the shaft of the device in the patent is supported at two points; namely, at one end similar to the bearing 28, 3|

in the instant application .and also by the engagementof a tapered surface on the perimeter of the disc like the surface SI of disc 4!! in the instant application; The result is that in the patented device when the assembly is adjusted in order to "varythe frictional engagement of the friction disc with its back plate or cooperating clutch member (andthepatent'ed device discloses only one such member), the entire shaft assembly may run out of. line, the shaft. being no longer concentric with the bearing 28, 3|, .andthe friction: disc only contacting overa partof its tapered surface 5| with the cooperating member. of the clutch. The result. is in some instances that uneven wear of the perimeter of theclu-tch member occurs-and it is necessary to obtain. a very preciseadjustment of the Working. partsin-orderto insure a smooth uniform operationand freedom from Wobble.

In operation an increased load is applied'ito the tapered surface 5| thereof more closely inven g'agement withthe corresponding tapered face on the back plate H], The result is an increase in friction between the friction disc 49 formin one clutch member and the back plate 19 forming a However, as the shaft 29 is supported at ends by the tapered bearings 28, 3|, and 21, 4| the shaft 29 remains substantially parallel, and the friction surface 5| of the friction disc remains substantially parallel to the cooperating surfaces on the clutch members ID. The result is that these friction surfaces-when engagedare engaged substantiall all the way around their 'perimeters and a smooth uniform tension results; This conditionis obtained by the fact that there is very little longitudinal movement of the friction disc relative to the plates In of the clutch as previously explained.

The device can therefore be set so that at the beginning of the winding operation with a small amount of film on the spool, where but little torque is necessary to wind same, the slippage between the frictionally engaged clutch members may be such that the pull upon the film will be just sufficient to maintain the same under the proper tension and prevent loose wrapping, or winding. As the convolutions of film build up with a resulting increase in the weight of the material and consequent need for .more torque, the clutch surfaces will be gradually urged into closer contact as the tapered portion 3| of member 30 moves outwardly upon the bearing surface 28 in response to the increasing load caused by the film at that end of the shaft. -This occurs because the bearing surface 21 moves inwardly contacting the taper 4| and pushing the disc 49 to the left. The twosurfaces 21 and 4| form a support the while for the outer end. of the shaft 29, and maintain the plane of the disc 49 perpendicular to the shaft and parallel to the cooperating member of the clutch.

It will be apparent from the foregoing that throughout the winding .operation the film being wound will be automatically maintained under a constant and uniform. tension irrespective of the number of turns upon the .spool or other carrier. The plates l9 and i6 are fixed relative to each other and forma .revolvable housing forming one member of the clutch of which housing the support 22 is merely an extension, and this housing supportsthe bearings 21, '28.. The shaft 29 extends through the housing'andis supported in the bearings therein, the clutch disc 4|Lbeing located between the bearings-asshown, and at least'one -(-2-'|') bearing being adjustable and engaging the disc 40- to move same along shaft29 to adjust the frictionas previously explained.

The advantages of this device will now be understood. Among the'advantages' are the follow- .ing:

A continuously even pull will be maintained on the material being wound on the spool which is mounted on a shaft 41 and turns therewith. As the weight on the spool increases the friction pressure on the clutch automatically and substantially correspondingly increases 'to insure continued winding. The advantage of the pres-- ent machine over applicants' prior Patent No. 1,705,899, issued March 19, 1929, is that in the present machine the friction all around the edge of the friction disc 40 is substantially uniform.

As the weight on the shaft increases, the left end of the shaft presses downwardly thereby pressing downwardly on'the bushing 39. The tapered surface 3| of the bushing 39 presses downwardly against, the inner tapered surface 28 of support 22 which is fixed. The bushing 30,

therefore, is pressed to the left, pressing against washers 32 and 34 and thrust bearing 33. This pressure causes a pressure against collar 35 to the left. A pull is hence created on the shaft 29 to the left. I 1 a Since the left end of the shaft 29 has a tendency to tilt downwardly due to the weight of the reel, and since the shaft has a tendency to move to the left due to the cam action of bushing 30 within tapered opening '28, the right hand end of the shaft has a tendency to press upwardly and move to the left. Since the tapered hub H of the friction disc 40 slides on the shaft, an upward pressure at the right hand end of the shaft will cause the tapered hub M to press against the tapered surface 2'! of the bushin 2|, and pressure of the shaft 29 to the left will cause the collar 44 to press against the Washers 43 and 42 and henceagainst the bushing 2| to the left, and the tapered surface of the hub 4! pressing against the tapered surface 21 of the bushing 2! causes the friction ,disc to move to the left and thereby pressing the peripheral edge of said'friction disc evenly all :around the surface 5| of clutch member Ill.

,Other advantages of this construction are as follows:

I vThe thrust ball bearing 33 reduces friction and givesouicker pick up when the reel starts. Furthermore',jthe taperedfbushingjfiil floatsfree on he shaft 29' and provides two bearing surfaces, one at the tapered surfaces '30, 28 and onethrough 'f'the axial opening in said bushing'35.

It 'will be noted further that the outer housing ,f-lB has -.a hub to journal the taperedbearing 2i. Said tapered bearinglturns 'within said clutch :housing IS. The tapered bearing 2i may turn either {with the clutch housinglli or with the tapered hub 4i ofthe friction disc 40, The collars 35and 44 merely hold the various parts'on the shaft in assembled relation and keep end play of the parts to a minimum.

. It will be noted that there is a clearance between the shaft 29 and the interior surface of the axial through opening of member 22.

What is claimed is: v

i 1. In a device of the character described, a

fixed sleeve support, a clutch member rotatable thereon, a shaft passing through said sleeve support, said sleeve support being formed at one end with a conical inner surface, a bushing slidable .on the shaft and having an external conical surface' contacting the internal conical surface of said sleeve support, a thrust bearing on the shaft,

a, collar on the shaft, said thrust bearin being interposed between said bushing and collar, means on the shaft and adjacent said collar to support a reel, a friction disc slidably mounted on the shaft and rotatable therewith, said clutch member and friction disc having contacting annular surfaces, said friction disc being formed with a hub pro- 1. vided with an external conical surface, a second i coll'ar on said shaft, and a bearinginterposed ;'between said hub and second collatihaving an in- T'ternal conical surface contacting the external 7 "if'conical surface of said hub.

' 2. In' a device of the character described, a

'ifixed sleevesup'port, a clutch member rotatable j, thereon, a shaft passingthrough said sleeve supifport, said sle'eve"supp'ort"beingformed at one end, with alconicaliriner surface, "a bushing slidableonthe shaft and having an external conical su'rface contacting the internal conical surface of ,,,said sleeve support, a thrust bearing on the shaft,

, a collar on the shaft, said thrust bearing being interposed between said bushing and collar, means on the shaft and adjacent said collar to member and friction disc having contacting an. nular surfaces, said friction disc being formed with a hub provided with an external conical surface, a second collar on said shaft, and a bearing interposed between said hub and second collar, having an internal conical surface contacting the external conical surface of said hub, and a clutch housing member attached to said clutch member and being formed with an annular sleeve surrounding said bearing.

3. In a device of the character described, a fixed sleeve support, a clutch member rotatable thereon, a shaft passing through said sleeve support, said sleeve support being formed at one end with a conical inner surface, a bushing slidable on the shaft and having an external conical surface contacting the internal conical surface of said sleeve support, a thrust bearing on the shaft, a collar on the shaft, said thrust bearing being interposed between said bushing and collar, means on the shaft and adjacent said collar to support a reel, a friction disc slidably mounted on the shaft and rotatable therewith, said clutch member and friction disc having contacting annular surfaces, said friction disc being formed with a hub provided with an external conical surface, a second collar on said shaft, and a bearing interposed between said hub and second collar, having an internal conical surface contacting the external conical surface of said hub, a clutch housing member attached to said clutch member and being formed with an annular sleeve surrounding said bearing, and means attached to said clutch member and housing to receive a drive means for rotating said clutch member and housing member.

4. In a device for winding a reel, a fixed sleeve support formed with an axial through opening, a shaft extending through said opening, and beyond the opposite ends of said sleeve support, there being a clearance between said shaft and through opening, said sleeve support being formed with an inner conical surface at one end, a bushing on said shaft having an external conical surface contacting said inner conical surface, a collar on said shaft, said bushing being interposed between said support and said collar, means on said shaft and beyond said collar to support a reel to be wound, a clutch member rotatably mounted on said sleeve support and being formed with an annular clutch surface, a friction disc Slidably mounted on said shaft, means to cause said friction disc to rotate with said shaft, said friction disc having an annular friction surface adapted to contact the frictionsurface on said clutch member, said friction disc having a hub formed with an external con cal surface, a hearing surrounding said shaft and having an internal conical surface contacting the external conical surface of said hub, and means on said shaft to retain said bearing in contact with said hub.

5. In a device for winding a reel, a fixed sleeve support formed with an axial thro gh opening, a

. shaft extending through said opening, and beyond on sa d shaft having an external conical surface contacting said inner conical surface, a collar on said shaft, said bushing being interposed between said support and said collar, means on said shaft support-a reel, a friction disc slidably mounted on the "shaft and rotatable therewith,'said clutch 'rs and beyond said collar to support a reel to be wound, a clutch member rotatably mountedon "said sleeve support and being formed with an through opening,

annular clutch-surface, a friction disc slidably mounted on said shaft, means to cause said frictionqdisc to rotate with said shaft, said friction disc, having an annular friction surface adapted to contact the friction surface on said clutch member, said friction disc having a hub formed with an external conical surface, a bearing surrounding said shaft and having an internal conical surface contacting the external conical surface of said hub, and means on said shaft to retain said bearing in contact with said hub, and a thrust bearing interposed between said bushing and collar and surrounding said shaft.

6. In a device for winding a reel, a fixed sleeve support formed with an axial through opening, a

shaft extending through said opening, and beyondthe opposite ends of said sleeve support,there being'a clearance between said shaft and through opening, said sleeve support being formed with an inner conical surface at one end, a bushing disc having an annular friction surface adapted to contact the friction surface on said clutch member, said friction disc havinga hub formed with an external conical surface, a bearing surrounding said shaft and having an internal conical surface contacting the GXtI'Il'll conical surface of said hub, and means on said shaft to retain said bearing in contact with said hub, a thrust bearing interposed between said bushing and collar and surround ng said shaft, a clutch housing member attached to said clutch member and said friction disc being interposed between said clutch member and said clutch housing memher.

7. In a device for windin a reel, a fixed sleeve support formed with an axial through opening, a shaft extending through said opening, and beyond the opposite ends of said sleeve support, there being a clearance between said shaft and formed with an inner conical surface at one end, a bushing on said shaft having an external conical surface contacting said inner conical surface, a collar on said shaft, said bushing being interposed between said support and said collar, means on said shaft and beyond said collar to support a reel to be wound, a clutch member rotatably mounted on said sleeve support and ,being formed with an annular clutch surface, a

having an internal conical surface contactin the external conical surface of said hub, and means on said shaft to retain said bearing in contact -with said hub, a thrust bearing interposed between said bushing and collar and surrounding said shaft, a clutch housing member. attach-ed to said clutch member and said friction .disc being I interposed between said clutch member and said clutch housing member, said clutch housing said sleeve support being member being formed with an annularsleeve portion surrounding said bearing.

8. In a device for winding a reel, a fixed sleeve support formed with an axial through opening, a shaft extending through said opening, and beyond the opposide ends of said sleeve support, there being a clearance between saiclshaft and through opening, said sleeve support being formed with an inner conical surface at one end, a bushing on said shaft having an external conical surface contacting said inner conical surface, a collar on said shaft, said bushing beinginterposed between said support and said collar, means on said shaft and beyond said collar to support a reel to be wound, a clutchmember rotatably mounted on said sleeve support and being formed with an annular clutch surface, a friction disc slidably mounted on said shaft, means to cause said friction disc to rotate withsaid shaft, said friction disc having an annular friction surface adapted to contact the friction surface on said clutch member, said friction disc having a. hub formed with an external conical surface, a bearing surrounding said shaft and having an internal conical surface contacting the external conical surface of said hub, and means on said shaft to retain said bearing in contact with said hub, a thrust bearing interposedbetween said bushing and collar and surrounding said shaft, a clutch housing member attachedto said clutch member and said friction disc beinginterposed between said clutch member and said clutch housing member, said clutch housing member being formed with an annular sleeve portion surrounding said bearing,,said bearing being floatingly mounted onsaidshaft.

9. In a device for winding a reel, a fixed sleeve support formed with an axial through opening, a shaft extending through said opening and beyond the opposite ends of said sleeve support, there being a clearance between said shaft and through opening, said sleeve support being formed with an inner conical surface at one end, a bushing on said shaft having an externalconical surface contacting said inner conical surface, a collar on said shaft, said bushing being interposed between said support and said collar, means on said shaft and beyond said collar to support a reel to be wound, a clutch member rotatably mounted on said sleeve support and being formed with an annular clutch surface, a friction disc slidably mounted on said shaft, means to cause said friction disc to rotate with said shaft, said friction disc having an annular friction surface adapted to contact the friction surface on said clutch member, said friction disc having a hub formed with an external conical surface, a hearing surrounding said shaft and having an internal conical. surface contacting the external conical surface of said hub, and meansv on said shaft to retain said bearing in contact with said hub, a thrust bearing interposed between said bushing and collar and surrounding said shaft, a clutch housing member attached to said clutch member and saidfriction disc being interposed between said clutch member and said clutch housing member, said clutch housing member. being formed with an annular sleeve portion surrounding said bearing, said bearing being floatingly mounted on said shaft, the means for re taining the bearing in contact with said hub comprising a nut on the shaft and washers interposed between said nut and said bearing.

10. In a device for winding a reel, a fixed sleeve support formed with an axial through opening; a.

there being a clearance between said shaft and v 7 through opening, said sleeve support being formed with an inner conical surface at one end, a bushing on said shaft having an external conical surface contacting said inner conical surface, a collar on said shaft, said bushing being interposed between said support and said collar, means on said shaft and beyond said collar to support a reel to be wound, a clutch member rotatably mounted on said sleeve support and being formed with an annular clutch surface, a friction disc slidably mounted on said shaft, means to cause said friction disc to rotate with said shaft, said friction disc having an annular friction surface adapted to contact the friction surface on said clutch member, said friction disc having a hub formed with an external conical surface, a bearing surrounding said shaft and having an internal conical surface contacting the external conical surface of said hub, and means on said shaft to retain said bearing in contact with said hub, a thrust bearing interposed between said bushing and collar and surrounding said shaft, a clutch housing member attached to said clutch member and said friction disc being interposed between said clutch member and said clutch housing member, said clutch housing member being formed with an annular sleeve portion surrounding said bearing, said bearing being fioatingly mounted on said shaft, the means for retaining the bearing in contact with said hub comprising a nut on the shaft and washers interposed between said nut and said bearing, and a ring attached to the clutch mem- 10 her and being provided with means to receive a drive belt.

'11. In a device of the character described, a fixed sleeve support, a clutch member rotatable thereon, a shaft passing through said sleeve support, said sleeve support being formed at one end with'a conical inner surface, a bushing slidable on the shaft and having an external conical surface contacting the internal conical surface of said sleeve support, a thrust bearing on the shaft, a, collar on the shaft, said thrust bearing being interposed between said bushing and collar, a friction disc slidably mounted on the shaft and rotatable therewith, said clutch member and friction disc havin contacting'annular surfaces, said friction disc being formed with a hub provided with an external conical surface, a second collar on said shaft, and a bearing interposed between said hub and second collar, having an internal conical surface contacting the external conical surface of said hub.

JOSEPH CLAYTON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,398,680 Clayton Nov. 29, 1921 1,512,446 Barnes Oct. 21, 1924 1,705,899 Clayton Mar. 19, 1929 1,904,411 Clayton Apr. 18, 1933 2,078,893 Price Apr. 2'7, 1937 2,246,191 Schmitz June 1'7, 1941 

